Heat exchange element

ABSTRACT

The present invention relates to a heat exchange element in which unit constituent members, each of which includes a partition member that has a heat-transfer property and a moisture permeability and a spacing member that holds the partition member with a predetermined spacing, are stacked and in which a primary air flow that passes along an upper surface side of the partition member and a secondary air flow that passes along an undersurface side of the partition member and crosses the primary air flow exchange heat and moisture through the partition member, wherein a detachment suppressing rib is provided on the opposite side of the spacing member when viewed from the partition member at a bonded portion between the partition member and the spacing member, and the partition member is sandwiched by the spacing member and the detachment suppressing rib.

FIELD

The present invention relates to a heat exchange element that has astacked structure and exchanges heat and moisture between fluids in anair conditioner that supplies air from the outdoors to indoors anddischarges air from the indoors to outdoors simultaneously.

BACKGROUND

In recent years, air conditioning devices for heating, cooling, and thelike have become more advanced and widespread. As the residential areaswhere air conditioners are used grow, the importance of a total heatexchanger for an air conditioner, which can recover the temperature andhumidity during ventilation, is increasing. The total heat exchanger asdescribed above has a heat exchange element incorporated therein as anelement component that exchanges heat. This heat exchange element canexchange latent heat and sensible heat simultaneously without mixingfresh outside air drawn from the outdoors to indoors during the use ofan air conditioner with contaminated air to be discharged from theindoors to outdoors. The heat exchange element is required to have highgas-sealing properties and a high total heat exchange rate. Further, inorder to reduce power consumption of an air blowing device (such as afan or a blower) that circulates an air flow for ventilation and tosuppress the operating sound of the total heat exchanger to a low level,the heat exchange element is required to have a low air-flow resistancewhen each air flow circulates.

A conventional heat exchange element employs a structure in whichpartition members having gas-sealing properties, heat-transferproperties, and moisture permeability are stacked in multiple layerswith a predetermined spacing, where each of the partition members issandwiched between spacing members having a wave shape in cross section.In an example of the conventional heat exchange element, the partitionmember is a square flat plate, the spacing member is a wave-shaped plateformed into a triangular wave shape in cross section, and the partitionmembers are stacked with the spacing member sandwiched therebetween insuch a manner that the wave-shape direction of the alternate spacingmembers is turned by 90 degrees. Therefore, fluid paths in twodirections, through which a primary air flow and a secondary air flowpass, are formed in every two layers (Patent Literature 1). In this heatexchange element, the spacing member is wave-shaped. Therefore, there isa problem in that the effective area of an air-flow path formed betweenthe partition members becomes small because of the thickness of thiswave-shaped plate and further the area in which the partition member andthe spacing member are in contact with each other is large; therefore,the effective area of the partition member, which is capable of heatexchange, is small, thereby decreasing the total heat exchangeefficiency. Furthermore, because the spacing member is formed of paperor the like, there is a problem in that the cross-sectional shape of theair-flow path can be easily deformed, thereby increasing the air-flowresistance.

Therefore, in recent years, a method has been used, in which a resinmolded product is used as a spacing member of a heat exchange elementinstead of a wave-shaped plate, and a partition member and the resin areintegrally molded. With this structure, the degree of flexibility inshape of the heat exchange element is increased, whereby the total heatexchange efficiency is improved and the air-flow resistance is reduced(Patent Literature 2).

However, the method, in which the spacing member is molded integrallywith the partition member, has a problem of low adhesiveness of a bondedportion between the partition member and the spacing member. Further,because the partition member can expand and be deformed in high-humidityenvironment, the bonded portion is required to have an adhesive forcesufficient to withstand the deformation.

In recent years, mainly, for the purpose of reducing the amount of airleakage from a total heat exchange element and improving the moistureexchange efficiency, a partition member formed with high density hasbeen developed. This partition member has excellent properties as apartition member of the total heat exchange element, such as lowbreathability (air permeability) and better moisture permeability. Atthe same time, this partition member has a feature of a large amount ofexpansion/contraction, a small number of irregularities on the materialsurface, and a small number of cavities within the material. Therefore,when such a partition member is used, a sufficient amount of resincannot enter the cavities within the partition member and a sufficientanchor effect is not obtained in the bonded portion. Consequently, asufficient bonding strength cannot be obtained. Thus, when the partitionmember and the resin are integrally molded, they are bonded togetherimmediately after the processing; however, the partition memberrepeatedly expands/contracts because of a change in temperature andhumidity during use, thereby eventually causing the partition member andthe spacing member to come off their bonded surface. This blocks anair-flow path and therefore increases the air-flow resistance. As aresult, there is a problem of decreasing the total heat exchangeefficiency.

As a method for solving this problem, a heat exchange element has beenproposed, in which only a spacing member is integrally molded, andthereafter a partition member is affixed to the spacing member with anadhesive or the like (Patent Literature 3).

Another heat exchange element has been proposed, in which a cylindrical,triangular, or other-shaped convex portion is provided on a die formolding a spacing member and a partition member is held by the convexportion and embedded in the spacing member (Patent Literature 4).

CITATION LIST Patent Literatures

Patent Literature 1: Japanese Patent Publication No. S47-19990

Patent Literature 2: Japanese Patent Application Laid-open No.2003-287387

Patent Literature 3: Japanese Patent Application Laid-open No.2007-100997

Patent Literature 4: Japanese Patent Application Laid-open No.2008-70046

SUMMARY Technical Problem

In the above heat exchange element described in Patent Literature 3, inwhich only the spacing member is integrally molded, and thereafter thepartition member is affixed to the spacing member with an adhesive orthe like, it is necessary to increase the bonded area of the spacingmember and the partition member in order to enhance the adhesivestrength. Accordingly, the spacing member is required to be thick;therefore, the spacing member blocks the air-flow path to a largeextent, thereby increasing the air-flow resistance. As a result, thereis a problem of decreasing the total heat exchange efficiency.

Further, in the above heat exchange element described in PatentLiterature 4 mentioned above, in order to hold the partition member andembed it in the spacing member, the spacing member is required to have acertain thickness. Accordingly, the spacing member is required to bethick; therefore, the spacing member blocks the air-flow path to a largeextent, thereby increasing the air-flow resistance. As a result, thereis a problem of decreasing the total heat exchange efficiency.

The present invention has been achieved to solve the above problems andan object of the present invention is to provide a heat exchange elementwith a low air-flow resistance and high total heat exchange efficiencyby suppressing detachment of the partition member and the spacing memberfrom their bonded portion due to deflection of the partition membercaused by a change in temperature and humidity, even when a high-densityhigh-performance partition member is used and a spacing member has athin rib shape.

Solution to Problem

The present invention relates to a heat exchange element in which unitconstituent members, each of which includes a partition member that hasa heat-transfer property and a moisture permeability and a spacingmember that holds the partition member with a predetermined spacing, arestacked, and in which a primary air flow that passes along an uppersurface side of the partition member and a secondary air flow thatpasses along an undersurface side of the partition member and crossesthe primary air flow exchange heat and moisture through the partitionmember, wherein the spacing member includes first sealing ribs that areprovided on both sides of an upper surface of the partition member andparallel to a direction of the primary air flow, second sealing ribsthat are provided on both sides of an undersurface of the partitionmember and parallel to a direction of the secondary air flow, firstspacing ribs that are connected to the second sealing ribs and areprovided between the first sealing ribs and parallel to each other at apredetermined spacing, and second spacing ribs that are connected to thefirst sealing ribs and are provided between the second sealing ribs andparallel to each other at a predetermined spacing, and a detachmentsuppressing rib is provided on the opposite side of the spacing memberwhen viewed from the partition member at a bonded portion between thepartition member and the spacing member, and the partition member issandwiched by the spacing member and the detachment suppressing rib.

Advantageous Effects of Invention

The heat exchange element according to the present invention has astructure in which a partition member is sandwiched by using resin.Therefore, even when a high-density high-performance partition member isused and a spacing member has a thin rib shape, it is possible to obtainthe heat exchange element with a low air-flow resistance and high totalheat exchange efficiency by suppressing detachment of the partitionmember and the spacing member from their bonded portion due todeflection of the partition member caused by a change in temperature andhumidity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a heat exchange element according to afirst embodiment of the present invention.

FIG. 2 is a perspective view of a unit constituent member according tothe first embodiment of the present invention.

FIG. 3 is an enlarged view of part C in FIG. 2 according to the firstembodiment of the present invention.

FIG. 4 is a cross-sectional view of a detachment suppressing ribaccording to the first embodiment of the present invention.

FIG. 5 is an enlarged view of part C in FIG. 2 according to a secondembodiment of the present invention.

FIG. 6 is a cross-sectional view of a die used in a process ofmanufacturing a detachment suppressing rib according to the secondembodiment of the present invention.

FIG. 7 is a cross-sectional view of the detachment suppressing ribaccording to the second embodiment of the present invention.

FIG. 8 is an explanatory diagram of an arrangement spacing betweendetachment suppressing ribs in a heat exchange element according to thesecond embodiment of the present invention.

FIG. 9 is a diagram showing a relationship between an air flow and thedetachment suppressing ribs in the heat exchange element according tothe second embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS First Embodiment

A first embodiment of the present invention is explained with referenceto the accompanying drawings. FIG. 1 is a perspective view of a heatexchange element according to the first embodiment of the presentinvention. FIG. 2 is a perspective view of a unit constituent memberaccording to the first embodiment of the present invention.

As shown in FIG. 1, a heat exchange element 1 is formed by alternatelystacking unit constituent members 2 that are turned by 90 degrees. Eachof the unit constituent members 2 is configured from a partition member3 that performs heat exchange of the air passing along the upper sideand underside of the partition member 3 and that has heat-transferproperties, moisture permeability, and sealing properties, a spacingmember 4 that holds the partition member 3 with a predetermined spacing,and a deflection suppressing rib 7 that suppresses deflection of thepartition member 3. In the heat exchange element 1, a primary air flow Athat passes along the upper side of the partition member 3 and asecondary air flow B that passes along the underside of the partitionmember 3 exchange heat and moisture through the partition member 3.

Each constituent element of the heat exchange element 1 is explainedbelow in detail.

The partition member 3 serves as a medium through which heat andmoisture pass when heat and moisture exchange is performed between theprimary air flow A and the secondary air flow B. When the primary airflow A and the secondary air flow B pass through the partition member 3,a heat (or water vapor) temperature difference (or a water-vaporpartial-pressure difference) in a higher-temperature-side (orhigher-humidity-side) air flow is utilized on both surfaces of thepartition member 3 to move the heat and moisture from thehigher-temperature side (the higher-humidity side) to thelower-temperature side (or the lower-humidity side) through thepartition member 3, thereby exchanging the temperature (humidity). Atthe same time, the partition member 3 is required to prevent the primaryair flow A and the secondary air flow B from being mixed with each otherand to be able to suppress movement of carbon dioxide, odor, and othercomponents between the primary air flow A and the secondary air flow B.In order to satisfy these requirements, the partition member 3 has ahigh density, and preferably has a density of 0.95 [g/cm³] or higher, anair permeability resistance (JIS: P8628) of 200 seconds/100 cc orhigher, and moisture permeability. Specifically, the raw material of thepartition member 3 can be a Japanese paper, a fire-proof paper in whichinorganic additives are mixed, or other papers, such as aspecially-processed paper having undergone special processing or a papermade from a mixture of resin and pulp. The material of the partitionmember 3 can be a porous sheet (such as a nonwoven fabric or an expandedPTFE film) bonded with heat, an adhesive, or the like, to amoisture-permeable film having undergone chemical treatment to providethe functionality such as moisture permeability and flame retardancy orto a water-insoluble hydrophilic polymer thin film formed of resin thathas moisture permeability, such as polyurethane-based resin thatincludes an oxyethylene group, polyester-based resin that includes anoxyethylene group, or resin that includes a sulfonic acid group, anamino group, a hydroxyl group, or a carboxyl group at the terminal orside chain. Also, in a case of a sensible heat exchanger, the materialof the partition member 3 can be a resin sheet or resin film ofpolystyrene-based ABS, AS, or PS resin, or of polyolefin-based PP or PEresin, or other materials having only heat-transfer properties andgas-shielding properties.

In order to improve the heat-transfer properties, moisture permeability,and gas-sealing properties of the partition member 3, a manufacturingmethod is used in which cellulose fibers (pulp) are fibrillated bysufficient beating, and after making a paper by using the fibrillatedfibers, calendering (pressing) is performed on the paper by a supercalender or the like. The partition member 3 manufactured by thismanufacturing method has a thickness of approximately 20 to 60 μm, and adensity of 0.9 g/cm³ or higher, or extremely close to 1 g/cm³, or canhave a density even higher in some cases. As compared with normal papers(a thickness of approximately 100 to 150 μm and a density ofapproximately 0.6 to 0.8 g/cm³), the partition member 3 has ahigher-density structure. In terms of the gas-sealing properties,conventionally, polyvinyl alcohol that serves as a filler is applied toa porous paper in order to increase the air permeability resistance.However, when the partition member 3 is highly densified as describedabove, its holes are filled with the cellulose fibers themselves at ahigh density, and therefore the air permeability resistance ofapproximately 5,000 seconds/100 cc is ensured without performing suchspecial processing as described above.

When the partition member 3 that is highly densified as described aboveis used, the bonding of the partition member 3 to the spacing member 4becomes a problem. In a case where molten resin is poured onto thepartition member 3 described in the present embodiment to bond thepartition member 3 to the spacing member 4, it is almost impossible forthe resin to enter fine cavities and a sufficient anchor effect is notobtained, although this can also be related to the wettability of thepartition member 3 with the resin, or other factors. Therefore, thepartition member 3 and the resin are in a state where their respectivesurfaces are bonded together only by a chemical bond such as the Van derWaals force or a hydrogen bond. By pulling the partition member 3 andthe resin off each other, they come off their interfaces. Accordingly,sufficient long-term reliability of the bonded portion is not obtained.

The spacing member 4 has a function of maintaining the height of anair-flow path constant when the unit constituent members 2 are stacked.Specifically, the spacing member 4 constitutes the outer frame of theheat exchange element 1, and is configured from sealing ribs 5 that areprovided at both ends of the heat exchange element 1 parallel to anair-flow direction in order to prevent air leakage from the both ends,and a plurality of spacing ribs 6 that are provided parallel to thesealing ribs 5 and at a predetermined spacing and that maintain thespacing between the partition members 3 in a stacked direction when theunit constituent members 2 are stacked, to form an air-flow path.

As shown in FIG. 2, the sealing ribs 5 are formed along the peripheraledge of the unit constituent member 2, and are configured from firstsealing ribs 5 a that are provided on both sides of the upper surface ofthe partition member 3 and parallel to the direction of the primary airflow A, and second sealing ribs 5 b that are provided on both sides ofthe undersurface of the partition member 3 and parallel to the directionof the secondary air flow B.

The spacing ribs 6 are configured from first spacing ribs 6 a that areconnected to the second sealing ribs 5 b and provided between the firstsealing ribs 5 a and parallel to each other at a predetermined spacing,and second spacing ribs 6 b that are connected to the first sealing ribs5 a and provided between the second sealing ribs 5 b and parallel toeach other at a predetermined spacing.

It is necessary to set the height of the sealing ribs 5 and the spacingribs 6 so as not to block an air-flow path even when the partitionmember 3 expands after absorbing moisture.

Between the spacing ribs 6 adjacent to each other, a plurality of thedeflection suppressing ribs 7 that suppress blockage of an air-flow pathdue to the deflection of the partition member 3 are provided at apredetermined spacing and parallel to the spacing ribs 6.

Specifically, the deflection suppressing ribs 7 are configured fromfirst deflection-suppressing ribs 7 a that are connected to the secondsealing ribs 5 b and provided between the first spacing ribs 6 a andparallel to each other at a predetermined spacing, and seconddeflection-suppressing ribs 7 b that are connected to the first sealingribs 5 a and provided between the second spacing ribs 6 b and parallelto each other at a predetermined spacing.

The deflection suppressing rib 7 is formed with a smaller height and asmaller width than those of the spacing member 4. The sealing rib 5, thespacing rib 6, and the deflection suppressing rib 7 are formed on boththe upper surface and the undersurface of the partition member 3 withthose on the upper surface rotated by 90 degrees relative to those onthe undersurface. It is desirable for the deflection suppressing rib 7to have a thin, narrow shape so as to minimize the pressure loss ofventilating air and so as not to decrease the heat-transfer area and themoisture-permeable area of the partition member 3. Therefore, it isdesirable for the deflection suppressing rib 7 to have a small ribheight and a small rib width. Specifically, it is desirable that the ribheight of the deflection suppressing rib 7 is smaller than half the ribheight of the spacing rib 6 so as not to interfere with (contact) thedeflection suppressing ribs 7 on the upper and lower layers when theyare stacked. Further, because the width of the deflection suppressingrib 7 can be a cause of reducing the heat-transfer area and themoisture-permeable area, it is desirable to form the deflectionsuppressing rib 7 as thin as possible during molding.

This can be obtained by molding them with the partition member 3inserted into a die on which each shape of the sealing rib 5, thespacing rib 6, and the deflection suppressing rib 7 is cut. In additionto this, concave and convex portions and holes for positioning duringstacking, and a portion that receives a stripper for pushing a moldedproduct out of the die can be appropriately provided, for example. Theseportions have a function of maintaining the spacing between thepartition members 3 when a larger number of the partition members 3 arestacked.

The unit constituent member 2 has a substantially square shape (when theprimary air flow A and the secondary air flow B cross each other at aright angle) or a parallelogram shape (when the primary air flow A andthe secondary air flow B cross each other at an oblique angle). In orderto prevent product defects due to insertion misalignment at the time ofmolding the partition member 3 as much as possible and in order toincrease the reliability of preventing air leakage, generally, the widthof the sealing rib 5 is set greater than the width of the spacing rib 6.Particularly, when the occupation area of the spacing ribs 6 on thepartition member 3 is increased, this directly reduces theheat-transfer/moisture-permeable area of the partition member 3.Therefore, it is desirable that the width of the spacing rib 6 is assmall as possible. With the small width, the amount of resin to be usedcan also be reduced. The resin used for the spacing member 4 can bepolypropylene (PP) resin, acrylonitrile-butadiene-styrene (ABS) resin,polystyrene (PS) resin, acrylonitrile-styrene (AS) resin, polycarbonate(PC) resin, or other common resins capable of being molded into adesired shape. By molding the ribs with the resin as described above,deformation of the spacing member 4 due to humidity can be suppressed,and stable air-flow paths can be configured. Further, these resins canbe made flame retardant by adding a flame retardant, or can achieveimprovements in dimensional stability and strength by adding aninorganic substance. Depending on the object, it is also possible toachieve, for example, a reduction in the amount of resin by adding afoaming agent (a physical foaming agent/a chemical foaming agent) tofoam the resin.

FIG. 3 is an enlarged view of part C in FIG. 2 according to the firstembodiment of the present invention.

As shown in FIG. 3, the present invention has a structure in which thepartition member 3 is sandwiched from both sides by the seconddeflection-suppressing rib 7 b and detachment suppressing rib 8.

The detachment suppressing rib 8 has substantially the same shape as thesecond deflection-suppressing rib 7 b that sandwiches the partitionmember 3 from the opposite side with respect to the partition member 3.One end of the detachment suppressing rib 8 is bonded to the firstdeflection-suppressing rib 7 a and the other end thereof is bonded tothe first sealing rib 5 a.

However, if the detachment suppressing rib 8 is too large, it interfereswith the air flow flowing along a flow path. Therefore, it is desirablethat the detachment suppressing rib 8 is as thin as possible. However,if the detachment suppressing rib 8 is too thin, it cannot resist aforce that causes the partition member 3 to be deformed. Accordingly, itis necessary for the detachment suppressing rib 8 to have a heightgreater than the thickness of the partition member 3, and also equal toor lower than 15% of the height of one air-flow path, and moredesirably, equal to or lower than 10% of the height of one air-flowpath. Further, in order not to interfere with an air flow that contactsthe detachment suppressing rib 8, it is desirable that not only theheight of the detachment suppressing rib 8 but also the shape thereofare set so as not to have a high resistance against the air flow.

The second deflection-suppressing rib 7 b and the detachment suppressingrib 8 do not have a sufficient anchor effect between them and thepartition member 3. However, the second deflection-suppressing rib 7 b,the detachment suppressing rib 8, and the partition member 3 are bondedtogether by a chemical bond such as the Van der Waals force or ahydrogen bond.

FIG. 4 is a cross-sectional view of the detachment suppressing rib 8according to the first embodiment of the present invention.

In the above explanations of FIG. 3, the square shape in cross sectionthat is the pattern in FIG. 4(a) is used. However, taking the resistanceof the air in an air-flow path into consideration, it is preferable tohave an inverted-V shape, a trapezoidal shape, an elliptical shape, orthe like, which causes less air turbulence, in cross section taken alongthe direction of an air flow that contacts the detachment suppressingrib 8, as shown in FIGS. 4(b) to 4(d).

By employing the above configuration, when the partition member 3 issandwiched by the second deflection-suppressing rib 7 b and thedetachment suppressing rib 8, even if the partition member 3 expands andis deformed in high-humidity environment, the detachment suppressing rib8 can push the partition member 3 against a force that is appliedvertically to the bonded surface and that causes the partition member 3to come off the bonded surface. Further, one end of the detachmentsuppressing rib 8 is bonded to the first deflection-suppressing rib 7 aand the other end thereof is bonded to the first sealing rib 5 a. Thisrestricts the movement of the detachment suppressing rib 8; therefore,deformation of the partition member 3 can be suppressed.

Further, by sandwiching the partition member 3 between the seconddeflection-suppressing rib 7 b and the detachment suppressing rib 8, themoisture absorbing area is made smaller, and therefore the amount ofexpansion/contraction of the partition member 3 on the bonded surfacecan also be made smaller. Accordingly, a force that is generated becauseof the deformation is also made smaller. Even when the area of thepartition member 3 is reduced by sandwiching (covering) the partitionmember 3 by the detachment suppressing rib 8, the heat exchangeable areais not reduced because the second deflection-suppressing rib 7 b isprovided on the opposite side of the detachment suppressing rib 8.Therefore, sandwiching the partition member 3 between the detachmentsuppressing rib 8 and the second deflection-suppressing rib 7 b does notdegrade the heat exchange efficiency.

In FIG. 3 shown in the first embodiment, one end of the detachmentsuppressing rib 8 is bonded to the first deflection-suppressing rib 7 aand the other end thereof is bonded to the first sealing rib 5 a.However, both ends of the detachment suppressing rib 8 are notnecessarily bonded to the first deflection-suppressing rib 7 a and tothe first sealing rib 5 a. Even by simply sandwiching both surfaces ofthe partition member 3 by the detachment suppressing rib 8 and thesecond deflection-suppressing rib 7 b, detachment of the partitionmember 3 can be suppressed by the weight of the detachment suppressingrib 8.

In the first embodiment, the structure is employed in which thepartition member 3 is sandwiched by the second deflection-suppressingrib 7 b and the detachment suppressing rib 8. However, the same effectscan also be obtained from a structure in which the partition member 3 issandwiched by the detachment suppressing rib 8 and the firstdeflection-suppressing rib 7 a, the first sealing rib 5 a, the secondsealing rib 5 b, the first spacing rib 6 a, or the second spacing rib 6b.

The detachment suppressing rib 8 can be provided to all the firstsealing rib 5 a, the second sealing rib 5 b, the first spacing rib 6 a,the second spacing rib 6 b, the first deflection-suppressing rib 7 a,and the second deflection-suppressing rib 7 b, or can be provided tosome of them. By increasing the number of locations where the detachmentsuppressing rib 8 is provided, the effect of suppressing the detachmentis increased.

The heat exchange element according to the first embodiment of thepresent invention has a structure in which a partition member issandwiched by using resin. Therefore, even when a high-densityhigh-performance partition member is used and a spacing member has athin rib shape, it is possible to obtain the heat exchange element witha low air-flow resistance and high total heat exchange efficiency bysuppressing detachment of the partition member and the spacing memberfrom their bonded portion due to deflection of the partition membercaused by a change in temperature and humidity.

Second Embodiment

A second embodiment of the present invention is explained with referenceto the accompanying drawings. FIG. 5 is an enlarged view of part C inFIG. 2 according to the second embodiment of the present invention.Because the second embodiment is the same as the first embodiment exceptfor the structure of a detachment suppressing rib, the second embodimentis explained by focusing only on the structure of the detachmentsuppressing rib.

In the second embodiment, as shown in FIG. 5, the structure is employedin which the partition member 3 is sandwiched by the seconddeflection-suppressing rib 7 b and a detachment suppressing rib 9 and ispartially penetrated by these ribs (the second deflection-suppressingrib 7 b and the detachment suppressing rib 9 are integrated with thepartition member 3 sandwiched therebetween).

However, when the detachment suppressing rib 9 is too large, itinterferes with the air flow flowing along a flow path. This point isthe same as in the first embodiment. Therefore, it is desirable that thedetachment suppressing rib 9 is as small as possible.

The process of manufacturing the detachment suppressing rib 9 providedaccording to the second embodiment is explained below. FIG. 6 is across-sectional view of a die used in the process of manufacturing thedetachment suppressing rib 9 according to the second embodiment of thepresent invention.

As shown in FIG. 6, first, the partition member 3 is set on an upper die10 that includes an upper-die concave portion 10 a that is a concaveportion having a shape of the detachment suppressing rib 9, so as tocover the upper-die concave portion 10 a (S1 and S2). A lower die 11that includes a lower-die concave portion 11 a that is a concave portionhaving a shape of the deflection suppressing rib 7 is set (S3). Thelower die 11 includes a resin injection port 12 through which moltenresin can be injected. At this point, it is necessary to set the upperdie 10 and the lower die 11 such that a space created by the upper-dieconcave portion 10 a and the lower-die concave portion 11 a ispartitioned by the partition member 3. Among the partitioned spaces, thespace defined by the partition member 3 and the lower-die concaveportion 11 a is designated as a space A 13 and the space defined by thepartition member 3 and the upper-die concave portion 10 a is designatedas a space B 14. Next, molten resin obtained by melting thermoplasticresin is injected from the resin injection port 12 provided in the lowerdie 11 (S4). When the molten resin is injected, the space A 13 isgradually filled with the molten resin. At the time of injectionmolding, the pressure at which the molten resin is injected is so highthat a force is applied toward the low-pressure space B 14, and thepartition member 3 is broken through (S5). At this point, in thepartition member 3 that partitions the space into the space A 13 and thespace B 14, the center and its adjacent portion, where the highestpressure is applied, are broken through. Upon breaking through thepartition member 3, the pressure within the space A 13 is released inthe direction of the space B 14. Therefore, the molten resin is injectedinto the space B 14 and gradually fills the space B 14 (S6).Accordingly, the deflection suppressing rib 7 is molded by the space A13 and the detachment suppressing rib 9 is molded by the space B 14.Thus, the partition member 3 has a structure in which it is sandwichedby the deflection suppressing rib 7 and the detachment suppressing rib 9and is partially penetrated by these ribs. However, in order to breakthrough the partition member 3 by molten resin, first, high-pressuremolten resin pushes the partition member 3 and then the partition member3 gradually expands and is eventually broken when it expands beyond itsbreaking elongation. If the height of the upper-die concave portion 10 ais small, when the partition member 3 expands, it adheres to the wallsurface of the upper-die concave portion 10 a, and therefore theupper-die concave portion 10 a is filled with molten resin while thepartition member 3 remains unbroken. Accordingly, it is desirable tobreak the partition member 3 in order to more reliably bond thepartition member 3 and the molten resin together. In order to achievethis, there is an important relationship between the height of theupper-die concave portion 10 a, in other words, a height H of thedetachment suppressing rib 9, and the width of the contact portion ofthe upper-die concave portion 10 a and the partition member 3, in otherwords, a minimum width dimension W of the contact surface of thedetachment suppressing rib 9 and the partition member 3. The ratio H/Wis desirably large and is more preferably equal to or higher than 0.5(H/W≧0.5).

FIG. 7 is a cross-sectional view of the detachment suppressing rib 9according to the second embodiment of the present invention.

In the above explanations of FIG. 5, the elliptical shape in crosssection that is the pattern in FIG. 7(a) is used. However, taking theresistance of the air in an air-flow path into consideration, it ispreferable to have an inverted-V shape or the like, which causes lessair turbulence, in cross section taken along the direction of an airflow that contacts the detachment suppressing rib 9, as shown in FIG.7(b). Particularly, when the trapezoidal shape in cross section as shownin FIG. 7(C) is employed, an improvement in mold releasability from adie can be achieved in addition to the effect of reducing the resistanceof air that flows along an air-flow path.

Further, a diagram as viewed from an H direction in FIG. 7(c) is shownin FIGS. 7(d) to 7(f). FIG. 7(d) shows a so-called conical shape, inwhich the portion in which the partition member 3 and the detachmentsuppressing rib 9 are in contact with each other has a circular shapeand the top of the detachment suppressing rib 9 has a circular shape incross section. FIG. 7(e) shows a so-called elliptical conical shape, inwhich the portion in which the partition member 3 the detachmentsuppressing rib 9 are in contact with each other has an elliptical shapeand the top of the detachment suppressing rib 9 has also an ellipticalshape in cross section. This elliptical conical shape extendslongitudinally in the direction of an air flow. FIG. 7(f) shows aso-called combination of the conical shape and the elliptical conicalshape, in which the portion in which the partition member 3 and thedetachment suppressing rib 9 are in contact with each other has acircular shape and the top of the detachment suppressing rib 9 has anelliptical shape in cross section. This elliptical conical shape extendslongitudinally in the direction of an air flow.

The detachment suppressing rib 9 is provided on the deflectionsuppressing rib 7, the spacing rib 6, and the sealing rib 5, andtherefore cannot extend outside from these ribs. Accordingly, in a casewhere the portion in which the partition member 3 and the detachmentsuppressing rib 9 are in contact with each other has a circular shape,the area where the partition member 3 is sandwiched can be made largerthan that in the case of an elliptical shape. Thus, in FIGS. 7(d) and7(f), the area where the partition member is sandwiched becomes largerand thus the adhesive force becomes larger. In the case of FIGS. 7(e)and 7(f), in which the detachment suppressing rib 9 has a so-calledelliptical conical shape or a so-called combination of the conical shapeand the elliptical conical shape, which extends longitudinally (Lf>Lw)in the direction of an air flow flowing along an air-flow path, theair-flow resistance becomes lower than the case where the detachmentsuppressing rib 9 has a so-called conical shape. Therefore, in order tosatisfy both an adhesive force of the partition member 3 and a reductionin the air-flow resistance, the combination of the conical shape and theelliptical conical shape shown in FIG. 7(f) is more preferable.

By employing the above configuration, when the partition member 3 issandwiched by the second deflection-suppressing rib 7 b and thedetachment suppressing rib 9, even if the partition member 3 expands andis deformed in high-humidity environment, the detachment suppressing rib9 can push the partition member 3 against a force that is appliedvertically to the bonded surface and that causes the partition member 3to come off the bonded surface.

In addition to the structure in which the partition member 3 issandwiched by the second deflection-suppressing rib 7 b and thedetachment suppressing rib 9, the structure is employed in which thepartition member 3 is partially penetrated by these ribs (the seconddeflection-suppressing rib 7 b and the detachment suppressing rib 9 areintegrated with the partition member 3 sandwiched therebetween).Therefore, as compared with the case of the first embodiment in whichthe partition member 3 is simply sandwiched by the seconddeflection-suppressing rib 7 b and the detachment suppressing rib 8, agreater anchor effect can be obtained by using resin that enters theirregularities on the broken surface, thereby producing an effect thatthe partition member 3 can be bonded more rigidly. Further, because thevolume of resin used for the detachment suppressing rib 9 is smallerthan that in the first embodiment, the amount of resin to be used isreduced accordingly. The resin can be made flame retardant by adding aflame retardant, or can achieve improvements in dimensional stabilityand strength by adding an inorganic substance. Depending on the object,it is also possible to achieve, for example, a reduction in the amountof resin by adding a foaming agent (a physical foaming agent/a chemicalfoaming agent) to foam the resin. These points are the same as in thefirst embodiment.

In the second embodiment, the structure is employed in which thepartition member 3 is sandwiched by the second deflection-suppressingrib 7 b and the detachment suppressing rib 9 and is partially penetratedby these ribs (the second deflection-suppressing rib 7 b and thedetachment suppressing rib 9 are integrated with the partition member 3sandwiched therebetween). However, the same effects can also be obtainedfrom a structure in which the partition member 3 is sandwiched by thedetachment suppressing rib 9 and the first deflection-suppressing rib 7a, the first sealing rib 5 a, the second sealing rib 5 b, the firstspacing rib 6 a, or the second spacing rib 6 b, and is partiallypenetrated by these ribs.

The detachment suppressing rib 9 can be provided to all the firstsealing rib 5 a, the second sealing rib 5 b, the first spacing rib 6 a,the second spacing rib 6 b, the first deflection-suppressing rib 7 a,and the second deflection-suppressing rib 7 b, or can be provided tosome of them. By increasing the number of locations where the detachmentsuppressing rib 9 is provided, the effect of suppressing the detachmentis increased.

If a large number of the detachment suppressing ribs 9 are provided forthe purpose of suppressing detachment of the partition member 3,detachment of the partition member 3 can be suppressed. However, theoccupation ratio of the detachment suppressing ribs 9 in an air-flowpath becomes high and accordingly the air-flow resistance is increased.In contrast, if only a small number of the detachment suppressing ribs 9are provided, the occupation ratio of the detachment suppressing ribs 9in an air-flow path can become low. However, there is a possibility thatdeflection of the partition member 3 is increased, which may lead to anincrease in air-flow resistance. As a result, the air-flow resistance isincreased. Therefore, in order to suppress the air-flow resistance to alow level, it is necessary to examine the arrangement spacing betweenthe detachment suppressing ribs 9.

FIG. 8 is an explanatory diagram of the arrangement spacing between thedetachment suppressing ribs in a heat exchange element according to thesecond embodiment of the present invention. FIG. 8 is a cross-sectionalview of the second deflection-suppressing rib 7 b and the detachmentsuppressing rib 9 as viewed from an E direction in FIG. 5.

FIG. 8(a) is a diagram in which the unit constituent members 2 arestacked, each of which includes three detachment suppressing ribs 9 onthe second deflection-suppressing rib 7 b that connects the firstsealing rib 5 a and its immediately-adjacent firstdeflection-suppressing rib 7 a. This description focuses on thedetachment suppressing ribs on the second deflection-suppressing rib 7 bthat connects the first sealing rib 5 a and the firstdeflection-suppressing rib 7 a; however, it is not limited thereto.

The height of an air-flow path is represented as g [mm], the arrangementspacing between the detachment suppressing ribs 9 is represented as p[mm], and the rate of change in dimension of the partition member 3 atthe time of its expansion is represented as σ. The rate of change indimension σ is determined by dividing the length of the expanded portionof the partition member 3 by the reference length of the partitionmember before the expansion. The dimensions of the expanded portion ofthe partition member are defined as the dimensions of the expandedportion of the partition member 3, which has completely expanded afterhaving been left in environmental conditions where the relative humidityis extremely close to 100% RH for a sufficient period of time.

With reference to FIG. 8(b), a condition in which the partition members3 completely block the space between its immediately-adjacent detachmentsuppressing ribs 9 is explained below.

The temperature and humidity of air that flows between theimmediately-adjacent detachment suppressing ribs 9 can be considered tobe substantially uniform. Therefore, the partition members 3 thatrespectively constitute the upper surface and the lower surface betweenthe immediately-adjacent detachment suppressing ribs 9 can be consideredto expand by the same amount at their opposed position. Accordingly, ifeach of the partition members 3 that respectively constitute the uppersurface and the lower surface blocks half the air-flow path, the entirespace between the immediately-adjacent detachment suppressing ribs 9 iscompletely blocked. A condition in which the partition member 3 on theupper surface or the lower surface blocks half the air-flow path in thismanner is described below.

The length of the partition member 3 on the upper surface or the lowersurface between the immediately-adjacent detachment suppressing ribs 9after the partition member 3 has sufficiently expanded is represented asp(1+σ). The required length for the partition member 3 to block half theair-flow path is represented as p+2(g/2). Therefore, the followingrelationship holds.p(1+σ)=p+2(g/2)  (Equation 1)That is, when the following relationship is satisfied, the partitionmembers 3 completely block the air-flow path.p=g/σ  (Equation 2)Therefore, in order for the partition members 2 not to completely blockthe air-flow path, it is necessary to satisfy the followingrelationship.p<g/σ  (Equation 3)

By arranging the detachment suppressing ribs 9 so as to satisfy theabove requirement (Equation 3), the situation where the partitionmembers 3 completely block the air-flow path can be prevented.

Even if the partition members 3 that respectively constitute the upperand lower surfaces between the immediately-adjacent detachmentsuppressing ribs 9 do not completely block the air-flow path, if thepartition members 3 join each other, there are problems in that thesurface coating comes off, and upon the environmental changes, thepartition members 3 return to their original length at a slower speed.Therefore, it is preferable to arrange the detachment suppressing ribs 9in such a manner that the partition members 3 that respectivelyconstitute the upper and lower surfaces between the immediately-adjacentdetachment suppressing ribs 9 do not join each other.

With reference to FIG. 8(c), a condition in which the partition members3 start contacting each other is explained below.

The partition member 3 is deflected to the greatest extent at thehalfway point between the detachment suppressing ribs 9, which is themaximum-distance position from the detachment suppressing ribs 9.Therefore, when this halfway point reaches the halfway point of theheight g [mm] of an air-flow path, there is a possibility of thepartition members 3 to start contacting each other. The length of thepartition members 3 on the upper surface or the lower surface of oneair-flow path after the partition member has sufficiently expanded isrepresented as p(1+σ). Therefore, the following relationship holds.

$\begin{matrix}{{g/2} = \sqrt{\left( \frac{\left( {1 + \sigma} \right)p}{2} \right)^{2} - \left( \frac{p}{2} \right)^{2}}} & \left( {{Equation}\mspace{14mu} 4} \right)\end{matrix}$That is, when the following relationship is satisfied, the partitionmembers 3 that respectively constitute the upper and lower surfaces ofan air-flow path start joining each other.

$\begin{matrix}{p = \frac{g}{\sqrt{\sigma\left( {\sigma + 2} \right)}}} & \left( {{Equation}\mspace{14mu} 5} \right)\end{matrix}$Therefore, in order for the partition members 3 not to join each other,it is necessary to satisfy the following relationship.

$\begin{matrix}{p < \frac{g}{\sqrt{\sigma\left( {\sigma + 2} \right)}}} & \left( {{Equation}\mspace{14mu} 6} \right)\end{matrix}$As shown in (Equation 3) and (Equation 6), the arrangement spacingbetween the detachment suppressing ribs 9 is proportional to the heightg of an air-flow path and is inversely proportional to the rate ofchange in dimension σ. Therefore, in a case where the height of theair-flow path is large, the arrangement spacing can be increased. In acase of using a partition member with a high rate of change indimension, it is necessary to reduce the arrangement spacing.

Further, in a case of providing the detachment suppressing ribs 9, it isdesirable that the positions of the detachment suppressing ribs 9 arealigned in the air-flow direction as much as possible within oneair-flow path as shown in FIG. 9 because this can further reduce theair-flow resistance. For example, as shown in FIG. 9(a), in a case of astraight flow path, it is desirable that the detachment suppressing ribs9 are aligned in a straight line parallel to the side walls of anair-flow path. Further, as shown in FIG. 9(b), in a case of a curvedflow path, it is desirable to arrange the detachment suppressing ribs 9such that they are aligned along a line substantially parallel to thewall surfaces of an air-flow path. Therefore, in another case where anair-flow path is widened/narrowed in stages, it is desirable to providethe detachment suppressing ribs 9 along a flow line of fluid.

REFERENCE SIGNS LIST

-   -   1 heat exchange element    -   2 unit constituent member    -   3 partition member    -   4 spacing member    -   5 sealing rib    -   5 a first sealing rib    -   5 b second sealing rib    -   6 spacing rib    -   6 a first spacing rib    -   6 b second spacing rib    -   7 deflection suppressing rib    -   7 a first deflection-suppressing rib    -   7 b second deflection-suppressing rib    -   8 detachment suppressing rib    -   9 detachment suppressing rib    -   10 upper die    -   10 a upper-die concave portion    -   11 lower die    -   11 a lower-die concave portion    -   12 resin injection port    -   13 space A    -   14 space B    -   A primary air flow    -   B secondary air flow

The invention claimed is:
 1. A heat exchange element comprising: aplurality of unit constituent members, each of which includes: apartition member that has a heat-transfer property and a moisturepermeability, a spacing member that holds the partition member with apredetermined spacing, and a deflection suppressing rib that suppressesdeflection of the partition member, wherein the unit constituent membersare stacked, and wherein a primary air flow passes along an uppersurface side of the partition member, and a secondary air flow passesalong an undersurface side of the partition member in a directiontransverse to the direction of the primary air flow, to exchange heatand moisture through the partition member, further wherein each spacingmember includes: first sealing ribs that are provided on opposite sidesof an upper surface of the partition member and parallel to a directionof the primary air flow, second sealing ribs that are provided onopposite sides of an undersurface of the partition member and parallelto a direction of the secondary air flow, first spacing ribs that areconnected to the second sealing ribs and are provided between the firstsealing ribs and parallel to each other at a predetermined spacing, andsecond spacing ribs that are connected to the first sealing ribs and areprovided between the second sealing ribs and parallel to each other at apredetermined spacing, and each deflection suppressing rib includes:first deflection-suppressing ribs that are connected to the secondsealing ribs and are provided between the first spacing ribs andparallel to each other at a predetermined spacing, and seconddeflection-suppressing ribs that are connected to the first sealing ribsand are provided between the second spacing ribs and parallel to eachother at a predetermined spacing, and each constituent member comprisesa detachment suppressing rib that sandwiches the partition memberbetween the detachment suppressing rib and at least one of the firstdeflection-suppressing rib and the second deflection-suppressing rib. 2.The heat exchange element according to claim 1, wherein the detachmentsuppressing rib is provided to both of the first deflection-suppressingrib and the second deflection-suppressing rib of the deflectionsuppressing rib.
 3. The heat exchange element according to claim 1,wherein at least one detachment suppressing rib and at least one firstdeflection-suppressing rib or second deflection-suppressing rib areintegrally connected by penetrating part of the partition member.
 4. Theheat exchange element according to claim 3, wherein a relationship ofH/W≧0.5 is satisfied, where W is a minimum width dimension of thedetachment suppressing rib at the surface of the partition member, and His a height of the detachment suppressing rib from the partition member.5. The heat exchange element according to claim 3, wherein a portion inwhich the detachment suppressing rib and the partition member are incontact with each other has a substantially circular shape in crosssection, and a top of the detachment suppressing rib has a substantiallycircular shape in cross section.
 6. The heat exchange element accordingto claim 3, wherein a portion in which the detachment suppressing riband the partition member are in contact with each other has asubstantially elliptical shape in cross section, a top of the detachmentsuppressing rib has a substantially elliptical shape in cross section,and these substantially elliptical shapes extend longitudinally along anair flow direction.
 7. The heat exchange element according to claim 3,wherein a portion in which the detachment suppressing rib and thepartition member are in contact with each other has a substantiallycircular shape in cross section, a top of the detachment suppressing ribhas a substantially elliptical shape in cross section, and thesubstantially elliptical shape of the top extends longitudinally alongan air flow direction.
 8. The heat exchange element according to claim3, wherein a relationship of p<g/σ is satisfied, where g is a height ofan air-flow path formed between two stacked unit constituent members, σis a rate of change in dimension of a partition member, determined bydividing a length of an expanded portion of the partition member whenthe partition member has expanded due to environmental conditions by areference dimension before the partition member expands, and p is aspacing between the detachment suppressing ribs.
 9. The heat exchangeelement according to claim 3, wherein the following relationship issatisfied: $p < \frac{g}{\sqrt{\sigma\left( {\sigma + 2} \right)}}$where g is a height of an air-flow path formed by stacking the unitconstituent members, σ is a rate of change in dimension determined bydividing a length of an expanded portion of the partition member whenthe partition member has expanded by a reference dimension before thepartition member expands, and p is an arrangement spacing between thedetachment suppressing ribs.
 10. The heat exchange element according toclaim 3, wherein the detachment suppressing rib is arranged in thedirection of an air-flow path.